Treatment of hydrocarbon oils



D. T. DAY. TREATMENT 0F HYDROCARBON OILS APPLICATION -FILED JUNE I7. I9I9.

I :Patented July` 1I, 1922.

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ATTONEYS.

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DAVID T. DAY, OF WASHINGTON, DISTRICT 0F COLUMBIA.

TREATMENT 0F HYDROCARBON OILS.

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To a?? [clio-n1 it may concern.'

Be it known that I. Davm T. DAY. a citi zen oi' the United States, residing at Washington. in the District of Columbia. have invented new and useful Improvements in theA Treatment of Hydrocarbon Oils. of which the following is a specification.

This invention relates to the converting of hydrocarbon oils having high boiling points into hydrocarbon oils having low boiling points. l

(')ne object of the invention is to provide a new and simplified process of cracking hydrocarbon oils and the elimination of the initial cause ot accidents and damage. com mon to apparatus and processes heretofore in use.

Another object of the invention is to subjectfthe hydrocarbons to be treated to a comparatively low degree of heat applied from the exterior of the retaining` vessel and to a high degree of pressure within said vessel directly to the hydrocarbons therein to heat the entire material to the desired temperature.

l am aware that high temperatures and various pressures have been used in the treatment of hydrocarbon oils and that these heavy oils have been brokennp thereby into other oils having lower boiling points. I am aware that several such processes have proved commerically successful for this purpose. These processes and all others known to me depend upon the application of external heat and cover ranges ot' temperature as high as 10000 C. and pressures have been mentioned as high as T00 pounds or more to the square`inch These processes use the external application of heat and the pressure developed by the expansion and de composition of the oils by the external application of such heat.

ln the application of these methodsot cracking oils, in the processes heretofore *invented and also as described in my Patent `:l:t826,089. it is customary to introduce into a still, in certain processes. hydrocarbon oils that are heavy and of high boiling point as compared with the oils resultant from the process. Similarly, in another well known process itis customary to introduce into a tube oils which by temperature conditions are at once changed into vapors. ln all these processes it is customary to effect the cracking ot the oils by heating the still or tubes Specification of Letters Patent.

Patented July 4l, i922.

with the result thatI the oil and vapor in one type of process and the vapor inthe second mentioned process gradually receive heat by conduction and convection with the necessary result that many diiierent stages oi' heating exist in the interior of the still or vapor tube. In the latter ease the rapid passage of the vapor through the tube effectually prevents all portions of the tube contents from being brought to the same ten1- perature with the result that when the temperature and pressure conditions desired for the cracking are obtained in one part of the tube they do not exist generally and to the same degree throughout the tube. Hence greater time is necessary in order that all portions of the vapor may surely be brought to the desired temperature. It follows also that by the time all portions have been sulficiently heated. part of the vapor has been heated far beyond the desired temperature with correspondingly deleterious eil'ect upon the products treated. since too high temperatures tend to produce products with bad odor and color and undue amounts of permanent gases.

The present invention has proved eliicient in treating hydrocarbon liquids and vapors with substantially perfectly uniform temperature. rlhis has resulted not only in a yield ot unusually superior and uniform products. a minimum of permanent gas and `tree carbon, tar and residues. but also in far greater rapidity in effecting the desired conversion.

rThis uniform heating at the cracking teniperature is eected by bringing the hydrocarbons to the desired temperature instantaneously by utilizing the heat obtained by compression of the vapor portion of the material treated until the entire material is heated to the desired temperature. lt is recognized that with the application of mechanical pressure to a vapor all parts of that vapor are compressed to an equal extent` so in the present invention all parts of the vapor share equally in the heat el'ect of the mechanical compression. lt will be observed here that this process is radically different from suelrprocesses previously mentioned herein as treating vapor because not only is the heat applied in a radically difierent and more efficient manner. all parts being treated equally at the same time. but it is also different in that this proces. 'may be applied version effect takes place.

to a vapor or to a mixture of vapor and liquid.l as in the case of a vapor containing particles of liquids in the state of drops frequently described as fog. The same difference in application of the heaty differentiates this process from those processes previously described as treating vapor and liquids and other cracking processes.

In carrying out the process the features of Which have been pointed out above it is customary to proceed as follows. The oil to be converted is first passed into a still which may be a series of tubes generally called a preheater. This still or system of tubes is cated in any Way which may prove efficient such as by coal, fuel oil, gas, superheated steam, or by the hot vapors provided by the process. By this means the oil is evaporated and brought wholly or partly in the form of vapor into any effective type of compressing apparatus or into a pi e heated by the compression of vapors. he compressor then acts on the vapor to compress the same so that the heat of compression uniformly raises the temperature and the degree of pressure to the point where the desired con- Then` by the usual or some special arrangement of valves in the compressor the vapor, or 'vapor and liquid, is expelled into a tube to be held at thls desired temperature and pressure` as by heat insulation. just long enough to effect the desired conversion. They are then exhausted through suitable control vents into cooling compartments which by exchan e serve to aid in raising the temperature of successive portions of oil to be treated.

One very essential feature of the process involves the temperature of the vapors produced in the preheater. It is necessary that these vapors be hot enough to remain as vapors until the end of the compression treatment. since if they were not sufficiently hot they would condense as soon as compression Was begun and once condensed the material could not be heated any further by compression. As previously stated one feature of the invention was to avoid the application of heat to thc exterior of a vessel while pressure was applied from within. It will thus be understood that no substantial pressure is provided in the preheater and that no appreciable heat comes into contact with the exterior of the compressor.

Another very essential feature of the invention iertains to the time element of the period of compression. It is of fundamental importance that the compression be brought from the lowest to the highest substantially instantaneously iny order that the heating action due. to compression may be effected. and without loss of heat through the walls of the compression chamber.

It is customary to retain in the system vapors which remain as such throughout the cycle and are not condensed in the cooling compartments hereinafter termed the condenser and circulate them around the vaporizing tubes or stills, and again, with the successive portions of oil to be treated into the com ression cylinder. As additional oil is intro uced into the system by flowing it into the preheater or vaporizing tube it takes heat from the uncondensed hot vapors returning from the compression tube and condenser and enters the compression tubey already partially heated. This heating action is due to the contact of the oil with the hot vapors, the heating of the latter bein effected by the compressor whether or not high temperatures are initially effected in the preheater. This utilization of the heat from the vapors results in an unusual economy.

It is recognized that it is frequently desirable to change the condition of pressure without disturbing the tem erature of conversion. Inasmuch as the nal temperature of conversion is brought about byE mechanical compression it would appear at first sight that the conversion temperature could not be altered without also effecting the pressurey i fog due to the current of vapor entering andy leaving the compression unit.

Under certain conditions in the use of certain low boiling point or partially reduced oils, such as kerosene, it has proved of advantage to deliver the oil to be treated into the system by pumpin it to the desired pressure into a tank from w ich it is allowed to flow over a wire gauze screen or other spreading material in the conversion tube adjacent the compression unit, where it is volatilized and converted without the necessity of passing it through the compressor. The heat lof compression is in this instance furnished by the material discharged from the compressor which is at the conversion temperature and pressure. The apparatus used in this treatment of kerosene will be further explained in its. connection with the apparatus for conducting the entire process.

The distinct and great advantage provided by the present invention will be observed in the elimination of all the dangers of explolsion due to highpressure which has proved beyond the pressure limits needed for the work under consideration and far beyond the interior temperatures brought about by the mechanical heating by compression. It is obvious that in heating in previous cracking processes by the external application of heat it has been necessary to heat the oil containers considerably above the temperature desired for the oil inside in order that the oil, which is a poor conducting agent, may become sufficiently hot throughout its mass. This has often necessitated the heating of iron containers, such as stills and tubes, to temperatures where the metal softens and weakens suiiciently to allow it to blow out under the pressureused. This has been par ticularly true where coatings of coke have formed as result of the cracking on the inner side of the still or tube and have added further trouble by not allowing the heat to reach the oil. Tn the present invention by allowing the use of internal heating such a coating would act beneficially in separating the metal from the oil which is necessarily hotter than the metal.

The invention includes treatment of any material which heretofore has been used in cracking or distillation processes, as well as the various crude oils, shale oils, and other petroleum oils, their distillates or residues. lt follows that the great variety of materials which may be treated and the long list of possible derivatives obtained are to be had only by using a wide rangeof heat and pressure. in general terms the materials treated may have boiling oints ranging from 150 C. up to 350 C. a though materials may as readily be treated which have boiling points above or below the extremes noted here. The temperature applied to the pre-heater and to which the materials initially treated are subjected for vaporization may range from 150 to 500 C. and above. his range may be safely and readily varied as desired, inasmuch as the usual element of danger is not present, namely, the blow-outs and explosions due to high pressure within a vessel while high temperature is applied to the eX- terior of the same vessel.

The treatment within the compressor unit includes a pressure from 150 pounds to the square inch to 2,000 pounds to the square inch and upwards, and a temperature range from 250 C. to 800 C. and upwards. The great possibilities of this method and structure of apparatus at once become apparent with the safe use of such wide ranges of temperature and 1aressure. The ranges may be safely varied, becoming either higher or. lower, for either pressure or temperature or both as this step of the method does not require the external application of heat to the compressor unit. The exterior application of heat has been found to so weaken the walls of the compressor unit in the structures formerly used that when interior high pressures were used disastrous blow-outs have occurred. This was probably because intense exterior heat has been necessary before the liquid or vapor contents ot' the vessels have been sufficiently heated, the materials within the vessel not beinfr Ifood heat conductors for absorbing heat from the wall of the vessel. ll it is not desired to incur the weakening of the compressor walls by a mild heating, such walls may be heat insulated or protected' from: exterior radiation by the use of asbestos coverings or a double wall with a partial exhaustion of the intervening space. rThe structure of the third container where the conversion is completed is similarly heat in'- sulated in order to maintain the heat and pressure condition constant until the desired conversion is complete.

Any apparatus may be used which is capable of withstanding the pressures hereinbefore prescribed and which is capable of compressing the material suthciently quickly. It is necessary that each complete compression step be eected at least within one second. Three times in one second has been found effective and desirable. The process has been successfully conducted in an apparatus in which the compressor had a bore of 18 inches and a single reciprocating piston with a stroke of two feet. The process has been satisfactorily conducted by using an oil distillate of from 35 to 45 B. which was heated to provide vapors which were then compressed to effect cracking of the same. The resulting product contained about 10% of hydrocarbons belonging to the gasolene series and having an end point of lower than 150 C. The materials present were compressed into a space six inches long and six inches in diameter and at a rate of at least three times in one second. Tn the apparatus used the above mentioned reciprocating piston compressor was driven by an electric motor. The products taken from the apparatus were found to contain gasoline, whereas no gasoline was presentin the untreated material. It is not now thought possible that any type of compressor other than a reciprocating piston compressor having a single piston could function to bring the material to the temperature and` pressure indicated in the time indicated. A multiple stage compressor or a turbine compressor probably would not function suiiiciently quickly. rihe invention is considered broad enough to cover any apparatus used although at present the single piston compressor is the only known operative device to perform this work. The accompanying drawing which forms a part of this specification is a view partly in elevation and section indicating diagrammatically one arrangement of apparatus which may be used. 1 is a preheater or super- I heater provided with any suitable heating means which may use any form of' fuel, elec tricity, or the products resultant o f the process. No additional pressure is applied to the interior of the heater 1 which is shown as consisting of coils of pipes which may comprise a tank or other suitable vessel. 2 is an intake pipe for raw material to be treated leading from any suitable source. The material treated in the preheater or super-heater l, a portion at least of which has been vaporized, is conducted by suitable means through a pipe or lead 3, ast a valve 4 into a compressor unit 5, which is provided with no external application of heat, and connected to which is a reciprocating piston compressor to compress the vapor and its accompanying material to the desired degree of temperature and pres sure. Thus unit 5 may or may not'be heat insulated, as previously indicated. The material so compressed and heated within the member 5 is led past suitable valves into a third chamber 6v inwliich the same pressure and temperature conditions prevail, remaining there until Athe desired degree of conversion is complete. A constant flow of converted'mate'rials, residues and derivatives is conducted from the chamber 6, at approximately the same rate as the infiow thereto, through a condenser 7 and past a trap 8 in which the desired distillates and derivatives are caught. The exhaust products and unconverted material are returned either tothe interior of the pre-heater for another cycle cf f reatment or to the exterior thereof for In addition to the apparatus just described, additional apparatus is provided for the4 treatment of kerosene or other low boiling oils as has been he'reinbeiorementioned. l

This additional apparatus merely provides -a reservoirl chamber for'kerosene which is so connected to the apparatuspreviously described that kerosene may be led into the chamber 6 without the necessity of passinA it through the compressor or pre-heater. represents an -inletfor kerosene connected with a reservoir tank.B. `The compressor 5 is operated to compress-the kerosene within the tank B to the same pressure as is the pressure within the vconversion chamber 6. From B the kerosene under this equalized pressure is permitted by gravity to fiow into the chamber 6 and over suitable spreading material herein illustrated as wire gauze screen 6, In this instance the heat-of conversion is furnished by 'the hot vapors Within the chamber 6 as has hereinbefore been explained. After being converted the. material Amay be led into. the condenser and lcaughtin a suitable trap. This appara-tus for the treatment of kerosene or other semirefined products is preferably coupled tothe compressor of the apparatus and suitably provided with valves. Any other means may be used, however, to equalize the pressure in the kerosene reservoir B to the pressure in the other part of the apparatusy so that the kerosene may flow by gravity. The necessity of placing the oil or kerosene under pressure in the tank B is apparent from the fact that the conversion chamber 6 has an interior pressure approximately as great as form temperature conditions with-the result-i ing comparative simplicity of products so diHers from the successive changes involved in the gradual breaking down of oils in successive stages as the heating varies from one part of the apparatus to another, whichv has Y come to be considered characteristic of the comparatively slow cracking processes now in use, that it seems justifiable to describe the eect of the present invention as conversion as differentiated from the term cracking applied to the lesssimple results of the older and slower types of processes.

. From the foregoing it Will be obvious that the present invention has shortened the time period necessary 4for the reduction of hydrocarbon oils of low boiling points from those having higher boiling points; has simplified and made more uniform the products derived from the operation of the process and system of the invention, and has eliminated the source of danger and frequent cause of accident, heretofore common tostructures used in this art, by dispensing with the application of heat to the exterior of the chamber or container in which pressure is used to promote the conversion desired.

The invention described in the foregoing may be applied in any of the arts in which materials are cracked or distilled, changes in the relative location of the apparatus parts, and variation of degrees of heat and pressure may be made in any or all of these parts and in the steps of the process without departing from the scope of the invention.

. I claim:

1. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points, which consistsin vaporizing at least a part of the oil to be treated and immediately compressing the material so treated in a cylinder by the action of a sliding piston which moves substantially instantaneously to ger-- erate pressure and heat sufficient to heat and compress the vaporized material to the temperature and pressure of conversion.

2. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points, which consists in preheating the oil to be treated and immediately compressing the material so treated in the presence of a vapor in a cylinder by the action of a sliding piston which moves substantially instantaneously to generate pressure and heat suiiicient to heat and compress the vaporized material to the temperature and pressure of conversion.

3. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points, which consists in prcheating at least a part of the material to be treated in one container. passing the material so treated including a vapor into a'coinpressor cylinder, and immediately subjecting the material within said cylinder to the substantially instantaneously applied pressure of a single reciprocating piston which pressure is sufiicient to substantially instantaneously heat and compress the materials to the temperature and pressure ot conversion.

4. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points. which consists in preheating at least a part of the material to be treated in one container, passing the material so treated including a vapor into a compressor cylinder, and immediately subjecting the material within said cylinder to the substantially instantaneously applied pressure ot a single reciprocating piston moving at the rate ot at least three strokes per second. the compression from each stroke being suicient to substantially instantaneously heat and compress the material to the temperature and pressure of conversion.

5. The process of producing hydrocarbon oils havin low boiling points from hydrocarbon oils having high boiling points which consists in vaporizing at least a part of the oil to be treated and immediately silbjecting the material so treated substantially instantaneously to a pressure suicient to substantially instantaneously heat and compress the same to the temperature and pressure of conversion.

6. The process of producing hydrocarbon oils having 10W boiling points from hydrocarbon oil having high boiling points which consists in vaporizing at least a partV of the oil to be treated, immediately subjecting the material so treated substantially instantaneously to a pressure sufficient to substantially instantaneously heat and compress the same to thpe temperature and pressure of conversion, and maintaining this pressure and temperature until the desired conversion is complete.

7. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points which consists in subjecting the oil to be treated t0 the action ot' heat to vaporize at least a part ot' said oil, immediately subjecting the material so treated substantially instantaneously to a pressure sulicient to substantially instantaneously heat and compress the same to the temperature and pressure oi' conversion. Without the application ot.' exterior heat to said material. and maintaining this pressure and temperature until the desired conversion is complete.

8. 'lhc process ol' producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points which consists in vaporizing at least a part of the material to be treated in one container, immedately passing the material so treated into a second container and immediately subjecting the material within said second container substantially instantaneously to a i pressure sufficient to substantially instantaneously heat and compress the same to the temperature and pressure of conversion.

9. The process ot' producing hydrocarbon oils having low boiling points .from hydrocarbon oils having high boiling points Which consists in vaporizinr at least a part of the oil to be treated in one container. immdiately passing said material so treated into a second container. immediately subjecting the material in said second container substantially instantaneously to a pressure sullicient to substantially instantaneously heat and compress the same to the temperature and compression of conversion, and maintaining l this pressure and temperature until the desired conversion is complete.

10. rl`he process ot producing hydrocarbon oils having low boiling points from hydrocarbon oil having high boiling points which consists in vaporizing at least a part of the oil to be treated in one container, irnmediately passing `said material so treated into a second container, immediately subjecting the material in said container substantially instantaneously to a pressure suficient to substantially instantaneously heat and compress the saine to the temperature and compression of conversion, passing said material so treated in said second container into a third container Without change ot pressure or temperature, and maintainin the same temperature and pressure in sai third container until the desired conversion is complete.

11. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having hi h boiling points which consists in subjecting the oil to be treated to the action of heat to vaporize at least part of said oil and immediately subjecting the material so treated Substantially instantaneously to al pressure sucient to substantially instantaneously heat and compress the sa'me to the temperature and pressure of conversion Without the application of heat to the exterior of the contalner 1n which said pressure is applied to said materials.

12. The process of producing hydrocarbon oils having lovv boiling points from hydrocarbon oils having hi h boiling polnts which consists in preheating the oil to be treated and immediately subjectin the materil so treated in the presence o a vapor substantially instantaneously to a pressure suflicient to substantially instantaneously heat and compress the same to the temperature and pressure of conversion;

13. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points which consists in preheating at least a part of the material to be treated inone container, immediately passing the material so treated including a vapor into a second container and immediately subjecting the material within said second container substantially instantaneously to a pressure suiiicient to substantially instantaneously heat and compress the same to the temperature and pressure of conversion.

14. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points which consists in subjectlng the oil to be treated to the action of heat and immediately subjecting the material so treated including a vapor substantially instantaneously to a pressure sufficient to substantially instantaneously heat and compress the same to the temperature and pressure oftconversion Without the application of heat to the exterior of the container in which -said pressure is applied to said material.

15. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points which consistsin vaporizing at least a part of the oil to be treated and immediately4 subjecting the material so. treated substantially instantaneously to aV pressure suiiicient to substantially instantaneously heat and compress the same to the temperature and pres-- sure of conversion, the vapors produced being suiiciently hot before compression to remain as vapors until the compression is at its maximum and conversion is complete.

16. The process of producing hydrocarbon oils having low bolling points from hydrocarbon oil having high boiling points which consists in vaporizing at least a partl of the oil to be treated, immediately subjecting the material so treated Substantially instantaneously to a pressure suiiicient to substantially instantaneously heat and .compress the sametto the temperature and pressure of conversion, and .maintaining this pressure and` temperature until the desired conversion is complete, the vapors produced being sufliciently hot before compression to remain as vapors until the compression is at its maximum and conversion is complete.

17. The process of producing hydrocarbon oils having loW boiling points from hydrocarbon oils having high boiling points Whloli consists in subjecting the oil to be treated to the action of heat to vaporize at least part of said oil, immediately subjecting the material so treated substantially instantaneously to a pressure sufficient to substantially instantaneously heat and compress the same to the temperature and pressure of conversion, Without the application of exterior heat to said material, and maintaining this pressure and temperature until the desired conversion is complete, the vapors produced being sufliciently hot before compression to remain as vapors until the compression is at its maximum and conversion is complete.

18. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points which consists in vaporizing at least a part of the material to be treated in one` container, immediately passing the materials so treated into a second Vcontainer and immediately subjecting the materials within said second container substantially instantaneously to a pressure 'suflicient to substantially instantaneously heat and compress the same to the temperature and pressure of conversion, the vapors produced being sufficiently hot before compression to remain as vapors until the compression is at its maximum and conversion is complete.

19. The process of producing hydrocarbon oils having low boiling point-s from hydrocarbon oil having high boiling points which consists in vaporizing at least a part of the oil to be treated in one container, immediately passing said material so treated into a second container immediately subjecting the material in said second container substantially instantaneously t-o a pressure suiiicient to substantially instantaneously heat and' compress the same to the temperature and compression of conversion, and maintaining this pressure and temperature until the desired conversion is complete, the vapors produced being sufciently hot before compression to remain as vapors until the compression is at its maximum and conversion is complete. ,t

20. The process of producing hydrocarbon oils having low boiling points from' hydrocarbon oil having high boiling points which consists in vaporizing at least a part of the oil to be treated in one container, immediately passing said material so treated into a second container, immediately subjecting the material in said second container substantially instantaneously'to a pressure suicient to substantially instantaneously heat and compress the same to the temperature Leaaoae and compression of conversion, passing said material so treated in said'second container into a third container Without change of pressure or temperature, and maintaining the same temperature and pressure in said third container until the desired conversion is complete. the vapors produced being sufficiently hot before compression to remain as vapors until the compression is at its maximum and conversion is complete.

2l. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points which consists in subjecting the oil to be treated to the action of heat to vaporize at least part of said oil, and immediately subjecting the material so treated substantially instantaneously to a 'pressure sufficient to substantially instantaneously heat and compress the same to the temperature and pressure of conversion Without the application of heat to the exterior of the container in which said pressure is applied to said materials, the vapors produced being suiciently hot before compression to remain as vapors until the compression is at its maximum and con'- version is complete.

22. The process of producing hydrocarbon oils having low boiling points from ,hydrocarbon oils having high boiling points which consists in preheating the oil to be treated and subjecting the material so treated in the presence of a vapor substantially instantaneousl toa pressure suflicien't to substantially instantaneously heat and compress the same to the t-emperature and pressure of conversion, said vapor being suciently hot before compression to remaln as vapor until the compression stage is at its maximum and conversion is complete.

23. The process of producing hydrocarbon oils'having low boiling points from hydrocarbon oils having high boiling points which consists in preheatin at least a part of the material to be treate in one container, passing the material so treated including a vapor into a second container and immediately subjecting the material within said second container substantially instantaneously to a pressure suflicient to substantially instantaneously heat and compress the same to the temperature and pressure of conversion, said vapor being suiliciently hot before compression to remain as vapor until the compression stage is at its maximum and conversion is complete.

24. The process of producing hydrocarbon oils having low boiling points from hydrocarbon oils having high boiling points which consists in subjecting the oil to be treated to the action of heat, and immediately subjecting the material so treated including a vapor substantially instantaneously to a pressure sulicicnt to substantially instantaneously heat and compress the same to the' temperature and pressure of conversion Without the application of heat to the exterior of the container in Whichsaid pressure is applied to said material, said vapor being suiliciently hot before compression to remain as vapor until the compression stage is at its maximum and conversion is complete.

In testimony whereof I have hereunto set my hand.

DAVID T. DAY. 

